Midway through Monday’s oral argument in Janus v. American Federation of State, County, and Municipal Employees, Justice Sonia Sotomayor asked U.S. Solicitor General Noel Francisco, “[H]ow much is there unionization in the general corporate sector … or private sector?”

“I don’t have that number,” Francisco replied.

Francisco cited very few facts, in fact, even though he was asking the Court to reverse a 40-year-old precedent that allows public-employee unions to collect “agency fees” for the cost of representing non-member employees in collective bargaining. Along with William Messenger, staff attorney for the National Right to Work Legal Defense Foundation, he assured the justices that reversing that case—called Abood v. Detroit Board of Education—would cause no real problems for the states, their employees, or the unions those employees chose to represent them.

The record didn’t support that assurance, simply because … well, there is no record in this case. There is simply the claim, a longtime staple of conservative legal thinking, that Abood was wrong; there is the unspoken corollary that conservatives now at last have five votes and can get rid of it.

In legal terms, that’s a curious assertion. Courts claim to follow a principle called stare decisis, meaning that cases, once decided, are not to be overturned simply because new judges come on the Court, or new parties win elections, or newly tenured law professors think they were wrong; the radical step of voiding precedent is saved for cases that have been proven unworkable or unjust in the years since they were decided.

Brown v. Board of Education in 1954 reversed not one but three venerable Supreme Court decisions that spanned more than a decade—Plessy v. Ferguson (1896), Cumming v. Richmond County Board of Education (1898), and Berea College v. Kentucky (1908). Those cases had held that state laws requiring racial segregation were constitutional—as long as facilities for the races were “separate, but equal.”

The NAACP Legal Defense and Education Fund, founded in 1940, did not rush into court arguing they had always been wrong; instead, the LDF brought case after case demonstrating that facilities made “separate” by race could never, in any meaningful sense, be “equal.” By 1954, the facts the LDF cited convinced the justices that the segregation trilogy rule simply did not work; and thus, the Court unanimously overturned it.

Ordinarily, a case testing important constitutional questions would arise out of a trial of some sort, in which the two parties would present factual evidence—at least documents and affidavits, if not expert witness testimony—supporting their side. In Brown, for example, the NAACP plaintiffs called psychologists Kenneth and Mamie Clark to testify that their work with black children showed negative effects of segregation on their self-esteem (as measured, for example, by their choice of white dolls over dolls with African American features). The Clarks were cross-examined before a judge; the states defending segregation presented their own expert psychologist, Columbia University Professor Henry Garrett, to defend segregation. Brown’s record was rich in evidence about the nature of segregated schools and their effects on students. Confronting that evidence, the Court had a basis to conclude that the previous cases should be overturned.

There’s none of that in Janus.

Until 2010, all sides had regarded Abood as settled law. Then, in a public-employee-union case that did not present the issue, Justice Alito, writing the majority opinion, announced that Abood was entirely wrong and should be overturned.

In 2013, a group of home-health workers brought a case called Harris v. Quinn challenging the agency fees. Defeat for public-employee unions was avoided, however, when the majority decided that home-health workers couldn’t be covered by union contracts at all. Abood survived.

Then the powerful anti-union advocacy network brought a case called Friedrichs v. California Teachers Association, challenging “agency fees” in teachers’ unions. They filed that case in district court, then immediately asked the court to dismiss their own case, so they could appeal it without a trial and thus get it before the seemingly receptive Supreme Court without delay. The union told the court, “The Unions have not moved for judgment on the pleadings, as they would prefer to ground the judgment in a factual record.” But the court decided not to assemble that record; it granted the challengers’ motion to lose without a trial.

That case reached the Supreme Court in the fall of 2015. After argument on November 1, the anti-union forces seemed to be on the verge of victory. Then, in February 2016, Justice Antonin Scalia died unexpectedly. Without his deciding vote, the Court was tied and affirmed the Ninth Circuit, 4 to 4. Abood, improbably, still lived.

But while Friedrichs was pending, Illinois Governor Bruce Rauner had asked a federal court to decide that he didn’t have to follow Illinois’s state-employee-union statutes any more, since they were probably going to be unconstitutional any day now. The federal court responded that having to follow state laws isn’t an “injury” to a governor, so Rauner had no “standing”; in fact, there was no case.

At that point, Mark Janus, an Illinois state social worker who opposes agency fees, asked to join the case. The court allowed him to do so, even though, legally, there was no case for him to join—and then dismissed Janus’s claims because of Abood. He appealed; this week his case reached the Supreme Court, encumbered by no more facts than was Friedrichs.

In Monday’s argument, Francisco’s casual ignorance of labor statistics was not the only gap in the advocates’s knowledge. Messenger, the Right-to-Work fund lawyer, assured the justices that unions who represent non-members don’t incur any additional expense by doing so; he gave no source for this, simply his assertion that “there’s no reason why” it shouldn’t be so. Upending the labor law of 23 states, the District of Columbia, and Puerto Rico would be no big deal either, he said. “I submit the contracts will survive.” When Justice Elena Kagan asked him whether the contracts in those states had “severability” clauses (which would make the disruption slightly less), he admitted, “I couldn’t find a number for the public sector,” but added that he had “anecdotal” experience that many contracts do have such clauses.

Justice Stephen Breyer pointed out that California, in a brief supporting the union, contended precisely the opposite. Messenger dismissed that claim without really answering it, and pointed out that contracts eventually expire anyway.

David Franklin, who argued for the state of Illinois in defense of its “agency fee” law, told the Court that Messenger had been wrong to focus on the cost of contract negotiations. Unions also must represent workers in grievance proceedings, he noted, and that costs money: “We don’t know what percentage of the union’s activities are wrapped up with grievances.” In fact, he said, grievance-representation costs “can be three times, six times, seven times as much … [as] the line for collective bargaining. So to decide this case in an evidentiary vacuum on the basis of assumptions about how that speech breaks down or how those expenses break down would in our view be irresponsible.”

When David Frederick, representing the union, rose to argue, Kagan asked him about Messenger’s assurance that an anti-union victory wouldn’t disrupt labor relations. Frederick responded that, “Intangibly, there are plenty of studies that show that when unions are deprived of agency fees, they tend to become more militant, more confrontational, they go out in search of short-term gains that they can bring back to their members and say stick with us.”

Chief Justice John Roberts jumped in: “Well, the argument on the other side, of course, is that the need to attract voluntary payments will make the unions more efficient, more effective, more attractive to a broader group of their employees. What’s wrong with that?”

What’s wrong with that as a factual matter may be nothing; it may be everything. Without a record—without a good look at the studies Frederick referenced, and maybe the cross-examination of their authors—we simply have no idea what economic theory and history tell us about union behavior. But what’s wrong with this argument as a matter of law is that it’s being carried on in the dark, with no more grounding in facts than the average afternoon radio call-in show. A responsible course—as even Solicitor General Francisco seemed to admit—would be to remand the case for the creation of a factual record to supplant some of the airy theorizing the advocates (and the justices) engaged in.

But that would allow public-employee unions to carry on for another year or two. And that’s what’s really wrong with the whole Janus proceeding. The conservative justices don’t even try to hide it: The case is really about politics—about their feeling that public-employee unions are too powerful and that the policies they favor are hurting the country and they are all Democrats and they need to be stopped right away.

Justice Anthony Kennedy, who rarely hides his true thoughts, summed up what is really going on. When Franklin, for Illinois, suggested that states had an interest in negotiating with a “stable, responsible, independent counter-party,” Kennedy all but exploded:

It can be a partner with you in advocating for a greater size workforce, against privatization, against merit promotion, against—for teacher tenure, for higher wages, for massive government, for increasing bonded indebtedness, for increasing taxes? That’s—that’s the interest the state has?

A few minutes later, Kennedy asked Frederick, representing the union, the question that seems to be foremost on his mind. If the Court rules against the union, “the unions will have less political influence, yes or no?”

Free speech has no fiercer advocate than Professor Eugene Volokh of the University of California at Los Angeles. As a teacher of First Amendment law, director of a First Amendment amicus brief clinic, and a founder of the libertarian-leaning Volokh Conspiracy blog, Volokh lets almost no free-speech sparrow fall anywhere in the U.S. without weighing in, usually against government and in favor of free speech objectors. Supreme Court justices have cited his opinions six times. From personal experience, I know him to be merciless when he deems a fellow academic insufficiently militant in defense of speech values.

So when Volokh weighs in before the Supreme Court in opposition to a free-speech claim, that fact should spur a careful look on all sides. Last month, Volokh filed an amicus brief in Janus v. American Federation of State County, and Municipal Employees, the pending First Amendment challenge to “agency fee” agreements between government and public-employee unions. Volokh’s brief, in support of the union, argues that the fees are fully constitutional—that, in fact, the First Amendment simply doesn’t apply to this case.

Alas, there seems little chance that the justices will heed the Volokh-Baude brief; since 2011, Justice Samuel Alito has been on a mission to take down public employee unions. He seemed to be on the verge of victory in 2016, with a case called Friedrichs v. California Teachers Association. The death of Justice Antonin Scalia, it seems likely, deprived Alito of his fifth vote, and resulted in a 4-4 decision affirming the fees. Scalia’s replacement, Neil Gorsuch, seems likely to be the fifth anti-union vote.

The issue in Janus is this: federal law allows (but does not require) state governments to recognize state employees to form unions; it allows (but does not require) states to bargain collectively with those unions; it allows (but does not require) states to permit workers to choose a union as the “exclusive representative” for “bargaining units” of employees such as teachers, correctional officers, or child-protective service workers. Under federal law, a public-employee union contract can’t require the workers to join the union; but an “exclusive representative” must represent all workers in a bargaining unit, members or not. Workers who don’t wish to join may (if the state so decides) be required to pay an “agency fee,” designed to compensate the union for the expenses of representation—not just bargaining for a contract but often administering grievance, health, training, and other programs.

Under a 1977 case Abood v. Detroit Board of Education, a union cannot use fees for political, lobbying, or litigation activities that go beyond the scope of representation. To allow the union to spend such monies, the court held, would violate objectors’ First Amendment rights against “compelled” speech; on the other hand, compelling the union to represent workers who paid it nothing would encourage “free riders”—and undermine the state’s lawful choice to use collective bargaining to ensure harmonious relations with its workers.

Th Abood precedent (despite fierce criticism from the right) was reaffirmed by the court many times; but in 2011, Alito, in an opinion called Knox v. Service Employees International Union, proclaimed that Abood had been wrongly decided. In the public employee context, he argued, even bread-and-butter union issues (wages, health benefits, pensions, work rules) are “political” issues, and thus any payment of fees was “compelled speech.”

Picking up on his cue, such groups as the National Right to Work Foundation have begun a quest to overturn Abood. They came close with Friedrichs; Janus, which will be argued on February 26, poses the identical question. Most of the briefing on the union side has argued that Abood struck the right balance—that is, that the advantage to the state and to workers of effective collective bargaining outweighs what Abood called the incidental “an impact upon [objectors’] interests,” as long as the union rebated that part of the fees used for purposes like “legislative lobbying and in support of political candidates.”

Volokh and Baude are bolder. They argue that the agency fees paid by objectors simply do not implicate their First Amendment rights at all. Yes, they argue, Abood was wrong; but the error was “not in how it applied the new First Amendment objection [to the fees] it recognized. Rather, Abood erred by recognizing that objection in the first place.” Agency fees paid to a union, even when required by the government, are simply a requirement that individuals pay for speech activities designated by the government. And, they argue, “[c]ompelled subsidies of others’ speech happens all the time, and are not generally viewed as burdening any First Amendment interest.”

As examples, the professors cite caselaw permitting the government to fund pre-natal clinics but refuse to fund clinics that perform or advocate abortions; allowing the government to enact requirements that National Endowment for the Arts grants take into consideration “general standards of decency”; and allowing states to issue special license plates honoring some civic and recreational groups while refusing to issue them for groups like the Sons of Confederate Veterans. Governments, under the First Amendment, are allowed to engage in “government speech” on behalf of, say, health and safety, school vaccination, and patriotism—and need not refund tax dollars to taxpayers who object because they favor sickness and accidents, vaccine-free lifestyles, or treason.

In the “agency fee” context, of course, the government itself is not speaking; it is requiring employees to make a direct payment to a private group engaged in speech. Volokh and Baude argue that doesn’t make a constitutional difference: “[T]he government frequently conditions important activities on the purchases of speech-related services from private entities or individuals.” As examples, they cite rules requiring licensed professionals to purchase privately offered education and training services to keep their licenses, or (as some states do) requiring real estate purchasers to hire a lawyer to close a purchase of real property. “These and other instances of private speech funded by government mandate need not be viewpoint-neutral, nor must they be justified by a compelling governmental interest.” Indeed, they say:

Stripped of Abood’s unfounded First Amendment concerns, this is an easy case. The government has determined that collective bargaining is the best way to negotiate contracts and settle disputes with public employees. The government would undisputedly be free to establish a public collective bargaining agent, or to pay a private one directly from the public fisc. That it has chosen instead to pay its employees and then require them to hire the collective bargaining agent does not change the constitutional analysis.

The professors’ brief is elegant and probably right; but I doubt that their counsel will slow the court’s stampede to overturn Abood. As the late Justice Thurgood Marshall once said of an egregious Rehnquist-court turnabout, “Power, not reason, is the currency of this court’s decisionmaking.”

The effects of a loss for the union respondents in Janus will be felt in every state that allows collective bargaining. They will include a loss of negotiating power for the unions, benefits and protections for the workers—and, not coincidentally, effectiveness for the Democratic Party. Janus seems like a thoroughly partisan operation.

Not mentioned in the professors’ brief is this: if Abood is overturned, anti-union activists will next surely target “exclusive bargaining” contracts in the private sector as well. At present, their argument is that public employment contracts are “inherently political” because they are contracts with government. But any second-year big law associate could write a brief describing the “political” nature of private union contracts. Indeed, Justice Felix Frankfurter, writing in 1961, elegantly made that argument for them: “The notion that economic and political concerns are separable is pre-Victorian,” he wrote.

Street concerned a contract between a private employer, the Southern Railway System, and the Machinists’ Union. The government had no involvement other than through enforcement of the Railway Labor Act, which required employers to bargain with a union that had won the right to represent its workers. Six Justices nonetheless assumed that dissenting workers’ First Amendment rights were involved when the union used dues to lobby for legislation or support political candidates; five of the six rescued the union contract only by adopting a creative reading of the act. Though it said so nowhere, they reasoned, the act compels the union to reimburse objectors for their share of funds expended “for the support of political causes.”

Justice Hugo Black, a First Amendment absolutist, dissented from that (relatively tortured) reading; he thought Congress really had authorized the collection of dues for political causes—but that the entire union contract thus violated the First Amendment by requiring “workers to associate with people they do not want to associate with, or to pay their money to support causes they detest.”

Frankfurter (joined by Justice John Marshall Harlan) dissented as well, but from the other side; like Volokh and Baude, he argued that the First Amendment issue, assumed by the majority, was a chimera. “Plaintiffs here are in no way subjected to ... suppression of their true beliefs or sponsorship of views they do not hold,” he wrote. Their argument was “too fine-spun a claim for constitutional recognition.”

Expect to hear a lot more “fine spun” arguments about Street if Abood goes down, and to read about the breathless discovery that private union contracts are also “political speech” that must be blocked by the all-new First Amendment.